Oil-soluble polyvalent metal salts of alkyl mercaptomethyl phosphonic acid



United States Patent 3,177,233 OIL-SOLUBLE POLYVALENT NETAL SALTS F ALKYL MERCAPTOMETHYL PHQSPHON- 1C AEZID George M. (Ialhonn, Cleveland, Ohio, assignor to Shell Oil Company, New York, N.Y., a corporation of Delaware No Drawing. Filed Aug. 30, 1963, Ser. No. 305,810

1 11 Claims. (Cl. 260-4293) lain-V wherein Ris an oil-soluble hydrocarbyl group, such as an alkyl, aralkyl, alkaryl or cycloalkyl radical having at least 6 carbon atoms and preferably is a C alkyl radical, the R s are the same or different groups which may be hydrogen or a C alkyl radical and the Xs are oxygen or sulfur, preferably oxygen. The cationic portion of the salt is a polyvalent metal of variable or non-variable valence such as an alkaline earth metal, e.g., Ca,

. Mg, Be, Ba, Sr, or another polyvalent metal such as Cr,

Mn, Fe, Co, Ni, Cu, Zn,Cd, Al, or Sn, of which preferred ones are Fe, Ni, Cu, Zn, Cd, and Al.

The anionic portions of these polyvalent metal salts which are preferred are anions of acids which have the formula 0 OH Gin-1a 2.1 y1SCH1] 0R1 11 where R is the same as defined in (I) and preferably a C alkyl radical. The acidic compounds represented by the above formulas are prepared by reacting a mercaptan or mercaptide having at least 6 carbon atoms with a halomethylphosphono compound such as chloromethylphosphonic acid or chloromethylphosphonate or their thio derivatives, in a suitable solvent, such as an aqueous alcoholic solution, at reflux temperature and under inert conditions until the reaction is completed, which may require from 1 to about 5 days. The mercaptans include: aliphatic mercaptans, such as hexyl, octyl, decyl, dodecyl and octadecyl mercaptans; cycloalkyl mercaptans, such as cyclohexyl mercaptan and dicyclohexyl mercaptan; and aralkyl mercaptans, such as phenyldecyl ,mercaptan and benzyl mercaptan. Instead of the mercaptans, the corresponding mercaptides can be used such as the alkali metal, e.g., Naor K mercap'tides. Suitable halomethylphosphono compounds include chloromethylphosphonic acid, mono or dihydrocarbyl chloromethylphosphonates, e.g., mono or dibutyl chloromethylphosphonate, mono or di-2-ethylhexy1 chloromethylphosphonate, mono ordilauryl chloromethylphosphonate, mono or diphenyl chloromethylphosphonate, mono or dicyclohexyl chloromethylphosphonate, mono or 'dibenzyl chloromethylphosphonate, dibutyl chloromethyldithiophosphonate,

, diphenyllchloromethyldithiophosphonate, dibutyl chlorornethyltrithiophosphonate, and alkali metal salts such as Na and Kflsalts of chloromethylphosphonic acid, Na

acid and the-like.

3,177,233 Patented Apr. 6, 1965 A preferred method of making the thiarnethylphosphonates is to react a suitable mercapto compound, such as an alkali metal, e.g., Na or K, C1048 alkyl mercaptide with an alkali metal, e.g., Na or K, salt of chloromethylphosphonic acid in an alcoholic solution under reflux conditions and under an inert atmosphere to form the alkali metal salt of an alkyl mercaptomethylphosphonic acid. The salt is then treated with a strong acid such as hydrochloric acid to spring free the alkylmercaptomethylphosphonic acid, which can be converted into the desired polyvalent metal salts.

The following examples illustrate the preparation of the acid portion of the salt for use, in accordance with the present invention.

EXAMPLE I Equivalent Weight First Both Hydro- Hydrogen gBHS Found 49.1 9.4 12.0 11.2 261 132' Expected 49.2 9.4 11.94 11.54 268.3 134.1

EXAMPLE II The monobutyl ester of decylmercaptomethylphosphonic acid was prepared by fully esterifying the acid of Example I and thereafter partially hydrolyzing the dies'ter with alcoholic KOH under reflux conditions for about 24 hours.

The following additional representative compounds were prepared by the above method: octyhnercaptomethylphosphonic acid, phonic acid, cyclohexylmercaptomethylphosphonic acid,

benzylmercaptomethylphosphonic acid, butyl decylmerthe sodium salt thus formed with an excess of an aqueous captomethyl acid phosphonate, phenyl decylmercaptomethyl acid phosphonate, monobutyl dodecylmercaptomethyl acid thiophosphonate, monooctyl cyclohexylmer captomethylthio acid. thioplio sphonate. i

The above thiamethylpliosphonic acids are converted to the neutral or basic polyvalent metal salts by suitable means such as by neutralizing the acid with an aqueous solution of sodium hydroxide or carbonate and mixing solution of the desired polyvalent metal compounds such as a sulfate, nitrate, chloride, acetate or the like and removing -the precipitated organic polyvalent metal salt 'by suitable means, such as filtration, decantation, or ext The product of Example II was neutralized with, an

aqueous solution of sodium hydroxide to which was added an excess of an aqueous'rnixture of ferrous ammonium, sulfate at ambient temperature while constantly stirring dodecylmercaptomethylphosa the mixture. The iron thiophosphonate precipitated and the aqueous phase was removed by decantation. The salt was purified by dissolving it in benzene, separating the benzene from insoluble material, water-washing, and stripping the benzene from the purified product. The end product was a basic iron phosphonate, which may be represented by the formula T Fe- O--PCHzSC1oH2! (OH) O C 4H 2 and the product analyzed as follows:

Percent Percent Percent Fe P Found- 7. 14 9. 23 8. 32 Expected 7. 95 9. 12 8. 82

EXAMPLE IV Preparation of the neutral iron salt of the monoester of Example 11 The neutral salt of the rnonobutyl decylthiamethyl phosphonate was similarly prepared by following the general procedure of Example H1 in neutralizing the product of Example II with an excess of ferric nitrate. The neutral salt may be represented by the formula:

using cadmium nitrate as the neutralizing agent. The salt was dissolved in benzene and water-washed repeatedly and the solvents were then stripped off and the product analyzed as follows:

Percent Percent Percent Cd S P Found l4. 7 8. 85 8. 00 Expected 14. 83 8. 46 8. l8

EXAMPLE VI Preparation of zinc salt of monobatyl decylthiamethylphosphonate The zinc salt of monobutyl decylthiamethylphosphonate was prepared following the procedure of Example V using zinc chloride as the neutralizing agent and the product analyzed as follows:

Percent Percent Percent Zn P 6. 64 9. 08 8. 31 Expected. 9. 20 9.01 8. 72

The following illustrate additional metal salts of this invention: Cr, Mn, Fe, Co, Ni, Cu, Al and Zn salts of octylmercaptomethylphosphonic acid, dodecylmercaptomethylphosphonic acid, cyclohexylmercaptomethyl phosphonic acid, benzylmercaptomethylphosphonic acid, phenylmercaptomethylphosphonic acid, butyl decylmercaptomethyl acid phosphonate, phenyl decylmercaptomethyl acid phosphonate, monothiobutyl dodecylmercaptomethyl acid phosphona-te, monobutyl phenylmercaptomethyl acid phosphonate, monothiooctyl cyclohexy1mercapto methyl acid thiop-hosphonate and the like.

The additives of this invention are believed to be novel compounds. They are soluble in various hydrocarbons and mixtures thereof of wide boiling range. These are useful therein for varied purposes and generally in amounts of from about 0.0001% to about 10%, preferably from 0.001% to about 5.0% by weight.

The polyvalent metal salts of mercaptomethylphosphono compounds of this invention are outstanding additives for improving, or gelling or thickening various liquid hydrocarbon products, such as natural and synthetic hydrocarbon lubricating oils, fuels (gasoline, kerosene, gas oil, burner fuel oil), slushing oils and various industrial oils, e.g., metal working and drawing oils, quenching oils, textile oil-s, hydraulic oils, dielectric compositions and other industrial oils. They are particularly outstanding when added in small amounts to hydrocarbon fuels such as gasoline or kerosene or lubricating oils and lubricating compositions in imparting extreme pressure and anti-wear properties to such materials. These additives are particularly useful as antioxidants and as gel-ling agents for gasoline, fuel oils, and other light oil products.

In order to show the unexpected gelling properties which salts of the present invention possess, from 0.2% to 1% of the salts shown in Table I below were added to gasoline and the gelling effects noted.

TABLE I [B ase=gasoline1 Liquid, no change in physical state of the gasoline.

Liquid with about 10% increase in viscosity of the gasoline.

Liquid 30% increase in viscosity of the gaso- Liquid 40% increase in (8) 0.2% aluminum decylmercaptoethyl phosphonate.

(9) 1% aluminum decylmercaptoethyl phos phonate. 7

(l0) 1% iron monobutyl deeylphosphonate- (ll) 1% aluminum monobutyldecyl phosphona e.

vliscoslty of the gas- (12) 1% sodium monobutyldecylmercapto None (insoluble in methyl phosphonate. gasoline).

1 Gel=def1ned as a non-pourable mass, the viscosity of base gasoline increased by over 70-90%.

The addition of 2% of the additive of Example III to kerosene at ambient temperature formed a solid fuel composition capable of withstanding high temperatures, above 350 F., without essential change in structure or stability.

The addition of 400 parts per million of the additive of Example III to gasoline increased the viscosity of the gasoline 70%. i

The addition of 1% of additive of Example IV to JP-4 jet fuel yields a heavy oil of SAE viscosity and the ad:

Er k

dition of 1% additive of Example III to JP-4 fuel yields a sticky gel which can be burned without collapsing.

The addition of only 1% of the additive of Example VI to an SAE 30 refined mineral oil produced a grease.

The addition of 2% of neutral Al salt of decylthiamethylphosphonic acid to an SAE 30 refined mineral oil formed a grease.

Greases are also formed by addition to mineral oil (at ambient temperature) of from 1% to 5% of any of the following salts alone or in mixtures thereof:

Cd, Zn, Al, Fe, Sn, Mn, Mg, Ca, Ba, Be salts of dodecylthiamercaptophosphonic acid, benzylthiamethylphosphonic acid, butyl dodecylthiamethyl acid phosphonate, cyclohexyl decylthiamethyl acid phosphonate, butyl decylthiamethyl acid thiophosphonate.

I claim as my invention:

1. A polyvalent metal salt selected from the group consisting of Fe, Cd, Zn and A1 of an acid having the formula wherein R is an oil-soluble alkyl radical having at least 6 carbon atoms, R is selected from the group consisting of hydrogen, and an alkyl radical, and X is a chalcogen having an atomic number from 8 to 16.

2. The composition of claim 1 wherein R is a C1048 alkyl radical, R is a C alkyl radical, and X is oxygen,

3. The composition of claim 1 wherein R is a C1048 alkyl radical, R is hydrogen, and X is oxygen.

4. The composition of claim 1 wherein R is a C1048 alkyl radical, R is a C alkyl radical, and X is sulfur 5. A polyvalent metal salt selected from the group consisting of Fe, Cd, Zn, and A1 of C1048 alkylmercaptomethylphosphonic acid.

6. A polyvalent metal salt selected from the group consisting of Fe, Cd, Zn, and Al of a monoester of C1048 alkylmercaptomethylphosphonic acid.

7. Iron salt of C1048 alkylmercaptomethylphosphonic acid.

8. Iron salt of monobutyl ester of decyl mercaptomethylphosphonic acid.

9. Cadmium salt of monobutyl ester of decyl mercaptomethylphosphonic acid.

10. Zinc salt of monobutyl ester of decyl mercaptomethylphosphonic acid. a

11. Aluminum salt of monobutyl ester of decyl mercaptomethylphosphonic acid.

References Cited by the Examiner UNITED STATES PATENTS 2,346,155 4/44 Denison et a1 260-429 2,795,492 6/57 Aylesworth et al. 44-7 2,838,555 6/58 Goldsmith 2 260-461 2,838,557 6/58 Verley 260429.9 2,854,468 9/58 Max 260-461 2,881,201 4/59 Schrader 260-429 2,911,292 11/59 Baldeschwieler 44-68 2,947,693 8/60 Boyle et al. 260-429.9 2,971,019 2/61 Ladd et al 260-461 2,991,244 7/61 Pattenden et al. 252-327 FOREIGN PATENTS 751,755 7/56 Great Britain.

TOBIAS E. LEVOW, Primary Examiner. 

1. A POLYVALENT METAL SALT SELECTED FROM THE GROUP CONSISTING OF FE, CD, ZN AND AL OF AN ACID HAVING THE FORMULA 